In my experience if you build your own fixture or get one that is built with a high enough efficiency, using current LED tech for flowering can yield amazing results, not to mention you don't need to wear those color correcting glasses because the spectrum is near that of daylight.
The important thing to make sure of is using the correct spectrum and also that the light is actually rated for the power it says it is.
I built this true 400w fixture for just under $400 and it was very simple to do, no soldering at all just plugging wires in to ez connect terminals and the LED strips are rated to last for six years at near 100% efficiency and then they just go down a few percentile up to the 12 year mark and even after that it's a minor diminishment.
The other cool thing is they keep updating these LED strips to be more efficient so as new models or different spectrums come out you can always just swap out the strips for new ones.
Because the light is so evenly distributed the strips actually don't need to be mounted to heat sinks like I have them, you can build a frame for even cheaper than I did using flat almuminum stock from Home Depot. I chose to use the heat sinks to keep them extra cool.
I completely agree though, just having one small under powered LED light is only good for vegetative growth, I started out with a Mars Hydro 317 W purple light and I was surprised once I started investigating the current LED tech and how cheaply fixtures could be made with stuff mostly found at the local hardware store
I'd be more than happy to help on a build if anyone is looking to DIY a fixture.